Identification of filler type in cavities behind tunnel linings during a subway tunnel surveys using the impulse-response method

摘要

A method of recognizing the filler type in cavities behind a tunnel lining based on the acoustic response to impacts is considered. This method provides a comparison between response signal spectra registered on real objects and spectra of modelled signals obtained using finite-element modelling. The model takes into account the properties of solids and fluid filling the cavity. Filler material is identified from the maximum of the correlation coefficient R between spectral components of the modelled signal and the signal obtained during an actual survey of subway tunnels. In the given example, the correlation coefficient of the spectra when the void is filled with water is R = 0.91, which is higher than for other filling media.